Ammunition

ABSTRACT

A high temperature resistant caseless cartridge that minimizes the chance of accidental ignition. The cartridge has a first cylindrical nitro ester molded propellant charge that contains a telescoped projectile and is surrounded by a second cylindrical high temperature resistant molded propellant charge of a predetermined mixture of nitramine and a combustible polymeric binder.

United States Patent Quinlan et al.

[111 3,847,081 1 Nov. 12, 1974 3.480,49O 11/1969 Finger 149/92 3,628,456 12/1971 Harrell... 102/DIG. l X 3,688,698 9/1972 Quinlan 102/40 X 3,730,094 5/l973 Quinlan t. lOZ/DIG. 1

Primary Examiner-Benjamin A. Borchelt Assistant Examiner-H. .1. Tudor Attorney, Agent, or FirmEugene F. Stevens, 11]; Herbert Berl; William Sommer [57] ABSTRACT 6 Claims, 1 Drawing Figure AMMUNITION [75] lnvcntors: Joseph B. Quinlan; Arthur F.

Darrah, both of Philadelphia, Pa.

[73] Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.

[22] Filed: Dec. 20, 1972 [21] Appl. No.: 316,955

[52] US. Cl. 102/38, l02/D1G. 1 [51] Int. Cl. F42b 5/18 [58] Field of Search 102/38, 40, D16. 1; 149/92 [56] References Cited UNITED STATES PATENTS 2966,405 12/1960 Sloan 149/92 X 3345.945 10/1967 Quinlan IOZ/DIG. l X

\y l2- l1 AMMUNITION The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to us of 5 any royalty thereon.

This invention relates to ammunition and more particularly to a caseless cartridge.

1n the field of caseless ammunition a problem has existed wherein the molded nitro ester propellant charge of ammunition rounds sometimes ignited prematurely due to being placed in high temperature environments prior to the time the round is fired.

One of the objects of the invention is to provide a caseless cartridge of ammunition in which the chance of accidental ignition is substantially minimized.

Another object of the invention is to provide such an ammunition round having a maximum of environmental protection.

These and other objects, features and advantages will become more apparent from the following description and accompanying drawing which is an elevational sectional view of an ammunition round embodying the principles of the invention.

The preferred round of ammunition to which the invention is directed has a projectile l0 telescopingly received within a forward central passage 11 in a first cylindrically shaped nitro ester molded propellant charge 12. The molded charge has a relatively larger rearward central passage 13 that seats a booster seal 14, a primer cup 15 containing booster mix 16 and primer mix 17, and a primer seal 18. The internal surface defining the rearward recess 13 in molded charge 12 is coated with a combustible adhesive during assembly for securing seals 14, 18 and primer cup 15. The adhesive, which contains approximately 91 percent by volume of collodium and 9 percent acetone, is also applied to the forward and rearward surfaces of the primer cup for assembled securement to the seals l4, 18. The external or lateral surface of charge 12 is also coated with the adhesive when it is assembled within the surrounding second cylindrical high temperature resistant molded propellant charge 20 which has substantially the same length as charge 12. The adhesive is also applied to the forward and rearward end surfaces of both cylindrical charges 12, 20 and to the rearward surface of primer seal 18 so that both the forward or upper seal 21 and the rearward or lower seal 22 can be securely assembled across the corresponding forward and rearward ends of the concentrically assembled charges 12, 20.

Preferably, the nitro ester molded charge 12 is a single base composition and comprises the following constituents by weight:

nitrocellulose 92.8571 potassium sulfate 0.93 dinitrutoluene 5.57 diphenylamine 0.65

However, charge 12 can be made of other compositions including double base compositions. The primer cup 15, as well as booster and primer seals 14, 18 are also made of a single base nitro ester as in the above composition for charge 12.

The preferred high temperature resistant molded propellant charge 20 is a mixture of 84 percent by weight of a nitramine and 16% combustible polymeric binder, although an acceptable range for the nitramine is 87 percent wherein the polymeric binder would have a range of 13-20 percent. The preferred nitramine is HMX (tetranitrotetramethylenetetramine or homocyclonite) although RDX (trinitrotrimethylenetriamene or cyclonite) is a satisfactory cyclic nitramine alternate, and the preferred polymeric binder is polyacrylate with cellulose acetate or cellulose butrate serving as reliable alternates. The high temperature resistant molded propellant charge 20 preferably has a sidewall thickness of 0.015 to 0.025 inches, and the first and second cylinders 12, 20 have a predetermined weight ratio. of substantially 2:1.

Preferably, the upper and lower or forward and rearward seals 21, 22 are constructed of the same material as the high temperature resistant molded cylinder 20.

Various modifications, changes or alterations may be resorted to without departing from the scope of the invention as defined in the appended claims.

We claim:

1. A high temperature resistant telescope caseless cartridge comprising,

a first cylindrical single base molded propellant charge having a forward central passage containing a projectile completely encapsulated therein and a relatively larger rearward central passage,

a booster seal extending across said rearward passage adjacent said projectile,

a primer cup containing a booster mix'and a primer mix in said rearward passage with said booster mix adjacent said booster seal,

a primer seal extending across said rearward passage adjacent said primer mix,

a second cylindrical high temperature resistant molded propellant charge surrounding the periphery of said first cylindrical molded charge, said high temperature resistant molded charge comprising a cyclic nitramine selected from the group consisting of tetranitrotetramethylenetetramine and trinitrotrimethylenetriamene, and a polymeric binder selected from the group consisting of polyacrylate, cellulose acetate and cellulose butrate, and

a pair of end seals extending completely across the respective ends of said second cylindrical molded propellant charge, said pair of end seals being of the same material as said high temperature resistant molded charge.

2. The structure in accordance with claim 1 wherein said high temperature resistant molded propellant charge is a mixture of 80 87 percent by weight of said nitramine and 13 20 percent of said combustible polymeric binder.

3. The structure of claim 2 wherein said nitramine is tetranitrotetramethylenetatramine, and said polymeric binder is polyacrylate.

4. The structure in accordance with claim 1 wherein said high temperature resistant molded propellant charge is a mixture of 84 percent by weight of a nitramine and 16 percent combustible polymeric binder.

5. The structure of claim 4 wherein said nitramine is tetranitrotetramethylenetatramine, and said polymeric binder is polyacrylate.

6. The structure of claim 1 wherein the first and second cylinders have a predetermined weight ratio of substantially 2:1 

1. A high temperature resistant telescope caseless cartridge comprising, a first cylindrical single base molded propellant charge having a forward central passage containing a projectile completely encapsulated therein and a relatively larger rearward central passage, a booster seal extending across said rearward passage adjacent said projectile, a primer cup containing a booster mix and a primer mix in said rearward passage with said booster mix adjacent said booster seal, a primer seal extending across said rearward passage adjacent said primer mix, a second cylindrical high temperature resistant molded propellant charge surrounding the periphery of said first cylindrical molded charge, said high temperature resistant molded charge comprising a cyclic nitramine selected from the group consisting of tetranitrotetramethylenetetramine and trinitrotrimethylenetriamene, and a polymeric binder selected from the group consisting of polyacrylate, cellulose acetate and cellulose butrate, and a pair of end seals extending completely across the respective ends of said second cylindrical molded propellant charge, said pair of end seals being of the same material as said high temperature resistant molded charge.
 2. The structure in accordance with claim 1 wherein said high temperature resistant molded propellant charge is a mixture of 80 - 87 percent by weight of said nitramine and 13 - 20 percent of said combustible polymeric binder.
 3. The structure of claim 2 wherein said nitramine is tetranitrotetramethylenetatramine, and said polymeric binder is polyacrylate.
 4. The structure in accordance with claim 1 wherein said high temperature resistant molded propellant charge is a mixture of 84 percent by weight of a nitramine and 16 percent combustible polymeric binder.
 5. The structure of claim 4 wherein said nitramine is tetranitrotetramethylenetatramine, and said polymeric binder is polyacrylate.
 6. The structure of claim 1 wherein the first and second cylinders have a predetermined weight ratio of substantially 2:1. 